Preprints

Subset expansions of monoids, with V. Gould https://arxiv.org/abs/2511.13435

A new approach to the grammic monoid, with A. Malheiro https://arxiv.org/abs/2511.22514

Forbidden configurations for coherency, with V. Gould, arxiv.org/abs/2506.11321

Journal articles (MathSciNet reviews of my papers. My Google Scholar entry.)

[34] Free inverse monoids are co-context-free, with T. Brough, M. Kambites and C-F. Nyberg-Brodda, Semigroup Forum (to appear).
(Preprint version available at arxiv.org/abs/2511.00566.)

[33] Translational hulls of semigroups of endomorphisms of an algebra, with V. Gould, A. Grau and M. Kambites, Journal of Pure and Applied Algebra, Volume 230, Issue 4, April 2026.
(Preprint version available at arxiv.org/abs/2404.14005.)

[32] The structure of End(Tn), with V. Gould and A. Grau, Monatshefte für Mathematik, Volume 209, pages 1–37, (2026).
(Preprint version available at arxiv.org/abs/2307.11596.)

[31] Feasibility of Learning Weighted Automata on a Semiring, with L. Daviaud, Logical Methods in Computer Science, Volume 21, Issue 3, pp. 15:1–15:36 (2025).
(Preprint version available at arxiv.org/abs/2309.07806.)

[30] Representations and identities of plactic-like monoids, with Alan Cain, Mark Kambites and António Malheiro, Journal of Algebra 606 (2022), 819–850.
(Preprint version available at arXiv:2107.04492.)

[29] Tropical Representations of Plactic Monoids, with Mark Kambites, Transactions of the American Mathematical Society 374 (2021), no. 6, 4423–4447.
(Preprint version available at arXiv:1906.03991.)

[28] Linear functions preserving Green's relations over fields, with Alexander Guterman, Mark Kambites and Artem Maksaev, Linear Algebra and its Applications, Vol.611 (2021), pp.310-333.
(Preprint version available at arXiv:2007.09054.)

[27] Matrix semigroups over semirings, with Victoria Gould and Munazza Naz, International Journal of Algebra and Computation, Vol. 30, No. 02, pp. 267-337 (2020).
(Preprint version available at arXiv:1907.12518.)

[26] Geometry and algorithms for upper triangular tropical matrix identities, with Ngoc Mai Tran.
Journal of Algebra 530 (2019), Pages 470-507. (Preprint available at arXiv:1806.01835 .)

[25] Identities in unitriangular and gossip monoids, with Peter Fenner,
Semigroup Forum 98 (2019), Issue 2, pp 338-354.
(Preprint available at arXiv:1804.11100 .)

[24] NP-completeness in the gossip monoid, with Peter Fenner and Mark Kambites.
International Journal of Algebra and Computation, Vol. 28, No. 4 (2018), Pages 653-672.
(Preprint available at arXiv:1606.01026.)

[23] Identities in Upper Triangular Tropical Matrix Semigroups and the Bicyclic Monoid,
with Laure Daviaud and Mark Kambites.
Journal of Algebra, Volume 501 (2018), Pages 503-525.
(Preprint version available at arXiv:1612.04219.)

[22] Linear isomorphisms preserving Green's relations for matrices over semirings,
with Alexander Guterman and Mark Kambites.
Linear Algebra and its Applications, Volume 545 (2018), Pages 1-14.
(Preprint available at arXiv:1709.05277.)

[21] Tropical matrix groups, with Zur Izhakian and Mark Kambites.
Semigroup Forum, 96 (2018) Issue 1, pp 178-196.

[20] Face monoid actions and tropical hyperplane arrangements, with Mark Kambites.
International Journal of Algebra and Computation 27 (2017), no. 8, 1001-1025.
(Preprint version available at arXiv:1604.03016.)

[19] The Shortest Identities for Max-Plus Automata with Two States, with Laure Daviaud.
Proc. 42nd International Symposium on Mathematical Foundations of Computer Science (MFCS 2017),
in Leibniz International Proceedings in Informatics (LIPIcs), vol. 83, 48:1-48:13, Kim G. Larsen et. al (eds.), Dagstuhl, Germany, 2017.

[18] L. G. Kovacs work on Lie powers,
Journal of the Australian Mathematical Society, Volume 102, Issue 1 (2017) pp. 9-19. Special issue dedicated to the memory of Laci Kovacs.

[17] FP-injectivity of semirings, semigroup rings and Leavitt path algebras, with T. G. Nam,
Communications in Algebra 45 (2017), no. 5, 1893-1906.

[16] Pure Dimension and Projectivity of Tropical Polytopes, with Zur Izhakian and Mark Kambites.
Advances in Mathematics, 303 (2016), 1236-1263.
(Author accepted manuscript available at arXiv:1106.4525.)

[15] Convexity of tropical polytopes, with Mark Kambites,
Linear Algebra and its Applications, 485 (2015), 531-544.
(Preprint version available at arXiv:1411.1630v1.)

[14] Idempotent tropical matrices and finite metric spaces, with Mark Kambites,
Advances in Geometry 14 (2014), no. 2, 253-276.
(Preprint version available at arXiv:1203.2480v1.)

[13] Exact rings and semirings, with David Wilding and Mark Kambites,
Journal of Algebra, 388 (2013), 324-337.
(Preprint version available at arXiv:1212.5358.)

[12] Lie powers of the natural module for GL(2,K), with Karin Erdmann,
The Quarterly Journal of Mathematics, 64 (2013), 113-131.
(Preprint version available at arXiv:1105.4576v1.)

[11] Green's J-order and the rank of tropical matrices, with Mark Kambites,
Journal of Pure and Applied Algebra, 217 (2013), 280-292.
(Preprint version available at arXiv:1102.2707v1.)

[10] An algebraic approach to time borrowing, with David Broomhead and Steve Furber,
IET Computers & Digital Techniques, 7 (2013), issue 1, 1-10.
(Preprint version available at MIMS Eprints: 2012.60.)

[9] A modular version of Klyachko's theorem on Lie representations of the general linear group,
with R. M. Bryant. Mathematical Proceedings Cambridge Philosophical Society, 153 (2012), 79-98.
(Preprint version available by request.)

[8] Multiplicative structure of 2x2 tropical matrices, with Mark Kambites.
Linear Algebra and its Applications, 435 (2011), 1612-1625.
(Preprint version available at arXiv:0907.0314v1.)

[7] Lie powers and pseudo-idempotents, with Ralph Stöhr,
Canadian Mathematical Bulletin, 54 (2011), 297-301.
(Preprint version available by request or via MIMS Eprints:2008.57.)

[6] Periodicity of Adams operations on the Green ring of a finite group, with R. M. Bryant.
Journal of Pure and Applied Algebra, 215 (2011), 989-1002.
(Preprint version available at arXiv:0912.2933v1.)

[5] Free central extensions of groups and modular Lie powers of relation modules, with Ralph Stöhr.
Proceedings of the American Mathematical Society, 138 (2010), 3807-3814.
(Preprint version available by request or via MIMS Eprints:2009.27.)

[4] Adams operations on the Green ring of a cyclic group of prime-power order, with R. M. Bryant.
Journal of Algebra, 323 (2010), no. 10, 2818-2833.
(Preprint version available at arXiv:0912.1524v1.)

[3] Free centre-by-nilpotent-by-abelian groups, with Ralph Stöhr,
Bulletin of the London Mathematical Society, 41 (2009), no. 5, 795-803.
(Preprint version available by request or via MIMS Eprints:2008.51.)

[2] Lie powers and Witt vectors, with R. M. Bryant,
Journal of Algebraic Combinatorics, 28 (2008), no. 1, 169-187.
(Preprint version available at MIMS Eprints:2007.234.)

[1] Standard tableaux and Klyachko's Theorem on Lie representations,
Journal of Combinatorial Theory, Series A, 114 (2007), no. 1, 151-158.
(Preprint version available at MIMS Eprints:2005.52.)